<?php

interface i_shop_l_cart {

    public function is_in_cart($product_id);
    public function add_item($prudoct_id,$quantity=1);
    public function update_item($product_id,$new_qty);
    public function remove_item($product_id);
    public function remove_all();
    public function is_empty();    
    public function total_items();
    public function get_all_items();

    public function total_tax();
    public function total_discount();
    public function total_product_price();
    /**
     * This function returns the real amount in your cart.
     * It considers discount,tax,product prices but not special things like shipping etc.
     *
     * @return float 
     */
    public function total_cart_price();
    
}
?>
